Brewer, a Republican and staunch gun rights advocate, signed the bill preventing local governments from melting down the weapons obtained from these popular civic events. Before the new law, the state had allowed such firearms to be destroyed.

A spokesman for Brewer could not immediately be reached for comment late on Monday.

The bill had the support of the National Rifle Association and Arizona's Republican-controlled legislature. It cleared the state Senate earlier this month by an 18-12 vote. The state House approved the bill in March.

Supporters of the measure said municipalities were wasting taxpayers' money by not realizing the revenue from reselling turned-in weapons.

Opponents argued that it sent the wrong message and that the state needed to focus on the broader issue of gun control.

"This action by the governor is not only outrageous, but it is insensitive for us now to be putting these guns back on the streets," said state Senator Steve Gallardo, a Democrat and a leading opponent of the measure. "That's just plain wrong."

The law does not specify what penalties communities would face for violating its provisions.

Arizona became a battlefront in the national gun debate after a 2011 mass shooting outside a Tucson supermarket killed six people and left U.S. Representative Gabrielle Giffords gravely wounded.

Giffords, who has since left Congress, and her husband, retired astronaut Mark Kelly, have been pushing for tighter gun laws, especially in the wake of the December 2012 massacre at a Connecticut school in which a gunman killed 26 people, including 20 kids.